package com.diaosidadui;

public class Demo04 {
    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder();
        sb.append(1);
        StringBuilder sb2 ;
        sb2 = sb.append(2);
        System.out.println(sb);
        System.out.println(sb2);
        System.out.println(sb.append(3).append("abc"));
        System.out.println(sb.reverse());
        System.out.println(sb.length());
        String st = sb.toString();
        System.out.println(st);
    }
}
